Study On The Proliferation And Regulation Mechanism Of FGF5 And FGF21 In Dermal Papilla Cells In Cashmere Goats

The secondary hair follicles of cashmere goats can be divided into three stages: anagen,catagen and telogen.Dermal papilla cells(DPCs)located in mesenchymal,reacting as the center of the hair cycle triggered by paracrine signals,is a repository of nutrients,growth factors and pluripotent stem cells,which plays an important role in regulating of hair follicle development,and play a crucial role in the formation of hair follicles and hair shafts.The interaction between DPCs and epithelial cells is constant although the dynamic changes in hair follicle structure.Understanding the regulation mechanism of DPCs activation and proliferation provides theoretical basis to explore the mechanism of hair follicle growth in cashmere goats.It is reported that FGF5 and FGF21 are differentially expressed between anagen and telogen of cashmere goat,but the localization and action modes in skin tissues are still unclear.Therefore,in this study,single-cell transcriptome sequencing and immunofluorescence were performed to explore the location of FGF5 and FGF21,and the effects on DPCs proliferation was explored to provide theoretical basis for explaining the mechanism of hair growth in cashmere goats.The main results in this study were as follows:1.FGF5,FGF21 and their receptor FGFR1,FGFR3 expressed highly in goat dorsal skin during anagen.The single-cell transcriptome profiling and immunofluorescence showed that FGF5,FGF21,and FGFR1 expressed in dermal papilla region.2.The Ad-Easy adenovirus packaging system was used to add the coding sequence of FGF5 and FGF21 into adenovirus vectors.Then adenovirus pAd-FGF5 and pAd-FGF21 were successfully obtained.The titer of pAd-FGF5 and pAd-FGF21 was measured in DPCs,and the results showed that the overexpression efficiency were more than 750000 multiples.The expression levels of FGF5 and FGF21 in DPCs and cells culture medium at different times were detected by ELISA,and the optimal treatment time of pAd-FGF5 and pAd-FGF21 was 84 h.3.FGF5 and FGF21 restrained the viability of DPCs,and the Ed U positive cells were decreased significantly after FGF5 and FGF21 expression.The cell cycle analysis revealed that FGF5 decreased the percentage of DPCs in G2 and S phase,but FGF21 only influenced G2 phase.Moreover,the cell proliferation markers of MKI67 and PCNA were inhibited by FGF5 and FGF21.FGF receptor 1 and 3 were also significantly increased with FGF5 and FGF21 overexpression.4.The CTNNB1 level was decreased with the overexpression of FGF5 and FGF21,which inhibited the activity of TCF3 and C-JUN,and the expression of proliferation-related genes C-MYC and CCD1 was also decreased.FGF5 and FGF21 also inhibited the expression of cell cycle-related protein ERK and the expression of TBX3 was also decreased.Nevertheless,oxidative stress response factor SOD2,GSR and CAT were decreased after FGF5 and FGF21 overexpressed.In conclusion,this study revealed that FGF5,FGF21 and FGFR1 were expressed in dermal papilla region in goat dorsal skin.And the study found that FGF5 and FGF21 inhibited the proliferation of goat DPCs by regulating Wnt signaling pathway,which provides a theoretical basis for explaining the molecular mechanism of hair cycle conversion in cashmere goat.